摘要
通过共沉淀法和离子交换法成功制备出不同阴离子插层水滑石(layered double hydroxides, LDHs)并比较吸附性能,筛选出性能最佳的乙酸根插层的Mg_(2)Al-LDHs。考察乙酸根插层的Mg_(2)Al-LDHs吸附磷过程的吸附动力学、吸附热力学,通过X-射线衍射仪(XRD)、傅立叶红外变换光谱仪(FTIR)对CO^(2-)_(3)-Mg_(2)Al-LDHs前驱体、 Ac^(-)-Mg_(2)Al-LDHs 2种吸附剂吸附前、后样品进行表征。结果表明:Ac^(-)-Mg_(2)Al-LDHs对磷吸附过程符合准二级动力学模型和Langmuir等温热力学模型,属于自发吸热的单分子层吸附过程。由于CO^(2-)_(3)-Mg_(2)Al-LDHs层间碳酸根离子与层板结合过于紧密,磷酸根离子无法将碳酸根离子置换,因此CO^(2-)_(3)-Mg_(2)Al-LDHs以表面吸附为主;相较于CO^(2-)_(3)-Mg_(2)Al-LDHs, Ac^(-)-Mg_(2)Al-LDHs样品吸附过程中发生表面吸附和化学吸附,故吸附性能提升明显。
Different anionic intercalated hydrotalides(LDHs) was prepared successfully by coprecipitation and ion exchange methods, the adsorption properties of LDHs was compared, and the best Mg_(2)Al-LDHs with acetic acid root intercalation was screened out. The adsorption kinetics and thermodynamics of phosphorus adsorption by Mg_(2)Al-LDHs intercalated with acetic acid was investigated and determined by X-ray diffraction and Fourier transform infrared spectroscopy was used to characterize the samples of CO^(2-)_(3)-Mg_(2)Al-LDHs precursor and Ac^(-)-Mg_(2)Al-LDHs adsorbent before and after adsorption. The results show that the phosphorus adsorption process of Ac^(-)-Mg_(2)Al-LDHs conforms to the quasi-second-order kinetic model and Langmuir isothermal thermodynamic model, which is a spontaneous endothermic monolayer adsorption process. Because the carbonate ions in the CO^(2-)_(3)-Mg_(2)Al-LDHs layer bind to the laminate too tightly, phosphate ions can not replace the carbonate ions the surface adsorption of CO^(2-)_(3)-Mg_(2)Al-LDHs is the main method. Compared with CO^(2-)_(3)-Mg_(2)Al-LDHs, surface adsorption and chemisorption occur during the adsorption process of Ac^(-)-Mg_(2)Al-LDHs, the adsorption performance is significantly improved.
作者
杨保俊
金耀宗
王上海
王百年
YANG Baojun;JIN Yaozong;WANG Shanghai;WANG Bainian(College of Chemistry and Chemical Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《中国粉体技术》
CAS
CSCD
2023年第2期47-54,共8页
China Powder Science and Technology
关键词
水滑石
乙酸根
磷酸根
吸附剂
hydrotalcite
acetic acid root
phosphoric acid root
adsorbent
